This invention relates to cervical collars worn to immobilize or restrict the movement of the head.
Cervical collars are generally of two types, either stock ("off-the-shelf") in various sizes, or customized ("made-to-fit") for the individual patient. Because of the additional time, equipment and labor involved, the customized collar is less popular than the stock collar which can be made available in different standard sizes to accommodate various heights and circumferences of the neck.
The desirable qualities of a stock cervical collar include comfort, support and durability. Comfort requires that all portions of the collar in contact with the neck be soft and flexible, and also that the collar be lightweight. Support requires a certain amount of rigidity to immobilize the head and neck, with respect to both forward-backward and side-to-side movement. Durability requires that the collar not tear or lose its qualities of comfort and support, or otherwise wear out during a period of use exceeding several weeks or months.
In addition to the foregoing, the ideal cervical collar would be simple and economical to manufacture.
Heretofore, stock cervical collars have failed to meet one or more of these requirements. Exemplary of such prior art collars is that described in U.S. Pat. No. 3,756,226 which is commonly known as the Philadelphia collar. While perhaps the most popular of stock collars, the Philadelphia collar has several drawbacks. The Philadelphia collar has front and back halves made of a foam polymeric material which are held in place by an adjustable strap secured to each half by rivets extending through the foam material. Rigid reinforcing members are positioned vertically at the bight of each half, i.e. under the chin and along the spine at the base of the head. The foam polymeric material does not support the head so that side-to-side movement thereof is not adequately inhibited by the reinforcement added only at the bights. Moreover, the foam material tears easily, especially adjacent the strap. The reinforcement under the chin is uncomfortable because the support of the chin is concentrated on the relatively small area of the reinforcing member in contact with the chest, and also because the reinforcement is secured tightly to the neck against the trachea or Adam's apple.
Other types of prior art cervical collars are seen in U.S. Pat. Nos. 4,205,667; 3,662,057; 3,504,667; 3,042,027; and 2,818,063.